Prostate cancer is the second leading cause of death for men after lung cancer. Over 90% of prostate cancer goes undetected until it is untreatable and has spread to the bone and lymphatic system. Each year, over 400,000 men in the United States alone undergo prostate surgery, and over a billion dollars a year is spent on prostate treatment. More than 230,000 men are diagnosed with prostate cancer and 30,000 men die from it each year. The treatments for prostate cancer include mainly complete surgical removal and radiation therapy. Currently, the most popular treatment is complete removal of the prostate by means of a surgical procedure. However, like other surgeries, such a procedure is invasive and with wounds, and the patient needs a long recovery time, and especially, such surgery often results in side effects, such as incontinence and impotence.
Radiation therapy generally comprised of external radiation therapy and internal radiation brachytherapy. External radiation therapy is seldom used currently because of its excessive irradiation to other organs and tissues other than the prostate gland. Radiation brachytherapy is well known and is becoming a broadly acceptable treatment method. There are two types of brachytherapy: high dose radioisotope and low dose radioisotope. In the former manner, a catheter and an after loader are used, and the high dose radioisotope is transferred to the desired location by a wire with the catheter. The radiation stays in the patient's body for a relatively short time. In the latter manner, a number of radiation seeds are implanted into the patient's body by a array of hollow needles through which the seeds will pass; the seeds will be deposited into a pre-planned positions determined by the physician, so that an ideal irradiation assignment in the prostate gland can be acquired.
Low dose radioisotope brachytherapy has the advantages of minimally invasive treatment, low cost, low side effects, and keeping the prostate, which will increase the patient's self confidence. The most commonly used method for seed delivery into the prostate is by an array of hollow needles with stylet needles which are inserted into the patient's body guided by a template with regular interval chambers. The hollow needles retract from the prostate, and the stylet needles stay there; then the seeds are deposited in the predetermined locations. The whole process of seed implanting is under monitoring of a ultrasound probe. The current locations of needles and seeds are detected immediately, so that the necessary adjustment can be done to obtain an ideal seeds position accuracy. The final accuracy and effectiveness of low dose brachytherapy is greatly related to the ultrasound probe's position and motion accuracy.
Radioactive seed delivery and implantation into some organs of the patient is a common procedure in radiation brachytherapy, for instance, low dose brachytherapy to prostate cancer. Such seeds commonly are made of Palladium-103 or Iodine-125. A plurality of such tiny seeds are delivered into the body arranged in and surrounding the tumor obtaining required local irradiation and has as low as possible effect to other normal tissue.
Traditionally, the seed delivery procedure is commonly achieved by inserting a cannula which is a hollow needle into the body first, to make the needle tip reach the required location of the seed implantation. A stylet will push the seeds passing through the cannula until the seed drop from the cannula tip by which one seed will be implanted by this process. More seeds will be implanted while the cannula continues retracting and the stylet stays there. Currently, the seed implantation process is achieved by manual techniques assisted by a very simple device, which comprises a template with a plurality of guiding holes for needle insertion of the cannula and the stylet. An applicator for grade seed delivery and stylet positioning is broadly used in current art which requires operator's skillful manual operation; otherwise, a wrong number and wrong position of seeds maybe implanted, and seeds may drop. Such process is commonly guided by transrectal ultrasound image or by MRI.
U.S. Pat. No. 5,938,583 describes a combined precise implant needles and method, comprising an insertion stylet, a sleeve element which has a larger diameter than the stylet, and a needle in which radioactive seeds have been preloaded for implanting.
U.S. Pat. No. 6,311,084 shows a computer based method and apparatus for providing prostate brachytherapy using Interventional Magnetic Resonance Imaging. The invention allows a treatment plan to be developed and the implantation procedure to be performed initially in accordance with the developed treatment plan. Modification to the plan is made in real-time by the invention software module coupled to the IMR imaging system. In this system, all the operation of this invention is still done by manual way.
U.S. Pat. No. 6,796,935 introduces a seed implantation apparatus which can perform multiple seed implantation with its plurality of hollow needles, which can hold one more radioactive seeds. This apparatus also includes pistons for each of the hollow needles and a plate located behind the pistons with a rod and a mechanical trigger, wherein the actuation causes the plate to move the pistons into said needles. This invention's advantage is that it can deliver plurality of seeds in the same time, so that increase the efficiency.
U.S. Pat. No. 5,860,909 describes an applicator for implanting seeds at variably spaced locations in a patient's body. The apparatus includes a needle inserted into the body, a base member adapted to be maintained generally stationary with respect to a surface of the body during use, and a needle chuck, which is slidably mounted with respect to the base member, for releasably coupling the needle. The apparatus also includes a seed magazine mounted on the needle chuck for dispensing seeds into the needle bore, a stylet extendable through the needle bore for forcing seeds in the bore into the patient's body, and a barrel attached to the needle chuck. This invention is currently mostly used in many hospitals for prostate brachytherapy, but it is still manual operation, the operator has to do his tedious job carefully.
U.S. Pat. No. 6,869,390 describes an automated implantation system for radioisotope seeds, this invention is the latest development achievement in this field, in which a very complicated seed cartridge and a gantry type for supporting the needling mechanism are used. There are still many disadvantages of this system, a long time is needed for a practical and commercial product is obtained.
Concerning the ultrasound probe driving device, U.S. Pat. No. 5,931,786 describes a manual driving device to ultrasound probe or the same; gear racks are used to obtain the probe's forward and backward translational motion, which is driven by a hand knob. The template is located in the end of the support close to the patient body. Scale is also made in the side of guide rods for easy observation of the travel distance.
U.S. Pat. No. 5,871,448 introduces a stepper apparatus for use in the imaging/treatment of internal organs using an ultrasound probe. This apparatus includes a body portion, a support element for holding the ultrasound probe, a slide portion for moving the support element for holding the template. The ultrasound probe can be moved longitudinally. Rack and gear arrangement are used and dual motion of indexed and continuous motions can be achieved.
The above two inventions are commonly used apparatus for support and driving ultrasound probe now. But they have only translation motion, not suitable for sagittal scanning. There is a need to develop a multi-functional, easy operating, more accurate ultrasound probe driver which is integrated with the needling mechanism, an initial positioning passive platform and a supporting cart.
Seed implantation is tedious and costs much operating room time with low efficiency and low accuracy in current art. There is no a practical system obtained. It is necessary to develop an automated and ultrasound guided seed delivery system with more practical advantages including high efficiency and high accuracy.
Accurate intervention of surgical needles is very important in various medical diagnostic and therapeutic procedures like tissue biopsy, brachytherapy, anaesthesia, vaccinations, blood/fluid sampling, abscess drainage, catheter insertion, cryogenic ablation, electrolytic ablation, neurosurgery, deep brain biopsy, etc. Precise placement of needles in soft tissue is challenging because of several reasons such as tissue heterogeneity and elastic stiffness, tissue deformation and movement, unfavorable anatomic structures, needle bending, inadequate sensing, and poor maneuverability. Some of the factors such as needle bending, tissue deformation and movement are directly related to the force experienced by the needle during insertion. A portion of these forces and deformations depend on the needle geometry and insertion techniques. Therefore, understanding of the complex mechanism of needle interaction with soft tissue is an active research area.
Currently available breast or other biopsy devices rely on manual insertion of large gauge needles into the patient's tissue. Typically, a biopsy needle with a stylet is inserted into the abnormal tissue, under the guidance of an imaging modality, such as ultrasound or magnetic resonance imaging (“MRI”). The stylet is then removed. A syringe is attached to the needle, suction is applied through the syringe and then the needle is manually thrust into and out of the tissue to capture and remove cellular material. However, rather than cutting the tissue to enable collection in the needle bore, the thin needle tends to displace the tissue, especially rigid malignant tissue. Therefore, only a small number of cells may be obtained. Even after repeated attempts, a sufficient amount of tissue might not be obtained. Displacement of tissue also alters the frame of reference defined by the imaging modality.
To improve yield, larger bore needles have been used. However, the risk of damage to the tissues that the needle has to traverse to reach the area of pathology, as well as the risks of bleeding, infection and patient discomfort, rise with increasing needle thickness. Healing time may therefore be increased. Large needle core biopsy needles may also cause significant damage to certain organs, such as the lungs and the spleen. As with fine needles, displacement of movable tissues, such as breast tissue, is also a problem.
Significant tissue/organ deformation and movement (both translational and rotational) are observed during puncturing capsule of inner organs like prostate, liver, etc. or skin of external organs like breast, etc. These undesired deformation and movement can cause deflection of the needle and the target resulting in clinical complications such as vital tissue damage, misdiagnosis, under/over dosing with radiation, tumor seeding, etc. Although the biological tissue relaxes and regains the position partially, there are some organ rotation and deformation which do not recover during surgery and consequently the whole surgical plan becomes erroneous. Therefore, there remains a need for a biopsy need that substantially reduces needle puncturing force and tissue deformation, while improving targeting accuracy.
As diagnostic markers and tools become increasingly sophisticated, smaller and smaller cancers are detected in their earliest stages, confined to such organs as the breast. The traditional method for removing such cancers is open surgery. Surgery causes trauma to the patient, is often performed without real-time image guidance, and may result in unnecessary removal of healthy tissue and/or geographic miss of cancer. A certain number of less invasive, ablation techniques exist, including heating by radio-frequency (RF), ultrasound and laser. A common drawback across all these ablation techniques is that tissue cannot be removed from the body in its natural biological state for subsequent histological examination. Particularly, pathological status of the margin around the ablation is difficult to determine due to burning, making subsequent oncological management of the patient very uncertain. There remains a need to excise tissue without such difficulties.